What is this?

[catchMEifUcan]

While digging out the silencer... I noticed this du-dad (first picture, circled in red).

I thought, "wierd. what electrical goes into the wheel-well?" So, I followed it. It turns into a tube on the other side which leads over to the wheels, but it's not the brake line. The brake line is the thicker line right next to it.

So, what is it?

[frank29]

Originally Posted by catchMEifUcan

So, what is it?

Each wheel has an electrical "wheel speed sensor". It is part of the ESP system.

[catchMEifUcan]

Ah... thanks Frank!

[Model 57]

Oh yeah, anything with ABS will have a wheel speed sensor. They are also used in the operation of Traction Control.